Typically three unnamed sources with domain knowledge are required. It's telling that no editor chose to run this and Hersh has to self-publish. I wish you would reconsider the folks flagging this.
LRB was rightfully skewered. They did not apply customary rules such as:
- only use unnamed sources if no other sources will come forward
- highest levels of editorial and legal need to approve
- fact checkers vet the info
A gracious interpretation is that not being a paper of note in news LRB were unaware and published what did not pass rudimentary scrutiny possibly because editors were star struck. A cynical interpretation is that they had motivation to look the other way.
In any case, journalistic outlets had largely long stopped running Hersh because he was penning unsubstantiated and illogical conspiracy theories.